1 November 2011

Babies and blood glucose In a review in The British Journal of Nutrition of the current literature on maternal glycemia and the role of the dietary GI and its impact on pregnancy outcomes, the authors conclude: ‘Data from clinical studies in healthy pregnant women have documented that consuming a low-GI diet during pregnancy reduces peaks in postprandial glucose levels and normalises infant birth weight. Pregnancy is a physiological condition where the GI may be of particular relevance as glucose is the primary fuel for fetal growth.’

Prof Jennie Brand-Miller explains. ‘A woman’s body changes during pregnancy to ensure a steady supply of glucose to her baby,’ she says. ‘Glucose is the main fuel the baby uses to grow and it crosses freely from mother to baby through the placenta. How much glucose the baby receives depends directly on the mother’s blood glucose level and the rate of placental blood flow. If a woman’s blood glucose level is high, then higher levels of glucose will also be transferred to her baby. Babies make their own insulin from about 15 weeks to handle glucose. So the extra glucose stimulates the baby’s pancreas to make extra insulin. The extra glucose is metabolised and stored, making the baby grow bigger and fatter than normal. The good news for pregnant women is that by treating elevated glucose levels during pregnancy, the risk of any problems drops considerably. And this is where the GI comes to the fore. Foods with a low GI typically evoke a lower rise in blood glucose levels, making maintenance of normal glucose levels easier.’

Physical activity matters for managing BGLs When healthy young people cut back their physical activity by about half for three days, they doubled their postprandial glucose responses to their meals according to findings of a study in Medicine & Science in Sports & Exercise. ‘We now have evidence that physical activity is an important part of the daily maintenance of glucose levels,’ says author Professor John Thyfault. ‘Even in the short term, reducing daily activity and ceasing regular exercise causes acute changes in the body associated with diabetes that can occur before weight gain and the development of obesity.’ Thyfault monitored the activity levels and diets of 12 healthy and moderately active young adults. When the participants reduced their physical activity by 50% for three days while continuing to enjoy the same diet, the continuous glucose monitors that they wore showed significantly increased levels in BGLs after meals. ‘This study shows that physical activity directly impacts health issues that are preventable,’ says Thyfault. ‘It is recommended that people take about 10,000 steps each day,’ ‘Recent evidence shows that most Americans are only taking about half of that, or 5000 steps a day. This chronic inactivity leads to impaired glucose control and increases the risk of developing diabetes.’

What’s New?Event: World Diabetes Day is held on November 14. Each year WDD features a theme chosen by the International Diabetes Federation. The slogan chosen for this year's campaign is: Act on Diabetes. Now. Check the website to find out what’s happening.